Respiration method and apparatus of continuous positive pressure flow of air



Jan. 30, 1968 w. E. MCALLISTER 3,356,109

RESPIRATION METHOD AND APPARATUS OF CONTINUOUS POSITIVE PRESSURE FLOW OF AIR Filed Dec. 19,

v m Nm mm INVENTOR WALT ER EMCALLISTER Y MM/@AMM v uuSmo zormww AT TORN EYS United States Patent O RESPIRATION METHOD AND APPARATUS OF CONTINUOUS POSITIVE PRESSURE FLOW OF AIR Walter E. McAllister, Rio Lerma 339, Depto. 2,

Mexico City 5, Mexico Filed Dec. 19, 1963, Ser. No. 331,724 9 Claims. (Ci. 12S-145.5)

This invention relates to improvements in methods and devices to assist breathing, and, more particularly, to an improved method and apparatus for artificial respiration.

Mankind is afflicted by diseases and injuries that destroy or seriously interfere with the nerve cells normally controlling respiration. These injuries, such as brain trauma, and diseases as for example, bulbar poliomyelitis, frequently interfere with ordinary respiration to such an extent that the act of breathing must be assisted by mechanical equipment, or the aiicted person will suifocate.

Presently available devices, such as the Drinker respirator or iron lung, are cumbersome, uncomfortable and very costly to purchase and operate. The iron lung simulates normal respiration by alternately applying positive and negative pressures to the external wall of the chest, or thorax, causing the thorax to expand or contract accordingly. Thus as in normal breathing, the expansion of the individual lung is wholly determined by the position of the walls of the thorax. A muscle or vacuum controlled outward movement of the thorax draws the external surfaces of the lungs in the same direction, and establishes a sub-atmospheric pressure within the air passages of the lungs, therebycausing air to rush into the inner air passages of the lungs. Expiration of air -from the lungs is accomplished by an inward movement of the thorax, compressing the lungs and increasing the pressure in the air passages of the lungs, thus squeezing the air out of the lungs. The inward movement of the thorax can be caused by an increase in air pressure outside the chest, applied by an iron lung, or, as in normal breathing, by the elastic recoil of the parts of the body previously stretched during inspiration. Thus such devices, as the iron lung, are necessarily characterized by elaborate valves, pressure seals, vacuum seals, switches and timing devices, to match the pressure and vacuum cycle of the machine to individual breathing requirements.

Certain types of available artificial respiration devices, such as aeronautical oxygen systems for use in rareed atmospheres during limited periods of time, blow air directly into the lungs. Such devices, Iwhich force air into the lungs generally require breathing masks with intricate air inlet and outlet valves. The application of excessive positive pressure to the air passages in the lungs, moreover, is generally believed to compress the pulmonary capillaries, and thereby cause the blood to stagnate in the venous channels in the right Iside of the heart, While creating a deficiency of blood in the left side of the heart and the arterial outlets. This application of excessive positive pressure produces an immediate and undesirable drop in arterial blood pressure.

According to the present invention, these disadvantages are overcome since it has been -found that artificial respiration can be continued for long periods of time at continuous positive pressure without adverse physical effect, if a continuous stream of air with a positive gauge pressure of between about 3 centimeters of water and 100 centimeters of water is applied to the lungs.

More particularly, by closing the glottis valve in the throat and supplying a continuous stream of air directly to the lungs through a tracheal cannula, or the like, at a continuous positive pressure selected between the range of about 3 centimeters of water and 100 centimeters of water positive pressure, life-sustaining air is supplied to the lungs without exerting further muscular control. Air is exhaled, according to the invention, by` opening the glottis valve to permit the fresh air rushing into the lungs under continuous positive pressure to iiush out the lungs. Thus by reducing the air supply to a simple continuous stream of air under positive pressure, the need for elaborate valves, seals, switches and timing equipment is obviated. It is not necessary, moreover, to enclose a part of or the entire body in an air-tight cabinet or tank. Aspirating means for occasionally removing waste material from the lungs, where required, can also be included as an integral part of the respiration method and apparatus.

For a more complete understanding of the present invention, reference may be had to the accompanying drawings in which:

FIGURE 1 illustrates, in diagrammatic form, one embodiment of the applicants invention; and

FIGURE 2 shows an exemplary tracheotomy cannula as used to insuiate the lungs, according to the invention.

According to the invention, as viewed from left to right in FIGURE 1, fresh air for the purpose of artificial respiration is drawn from the free atmosphere through an intake conduit or tube 10. The tube 10 is interrupted by a separation device 11 which will be subsequently described. The separation device 11 is provided with a substantially air-tight jar 12 which receives a discharge portion 13 of the intake tube 10 and a suction portion 14 of a continuation tube 15. The suction portion 14 of the continuation tube 15 is in free communication with the intake conduit 10 to permit the free flow of air therebetween.

The continuation tube 15 provides a convenient channel for air to flow from the separation device 11 to an air cleansing and humidifying device 16. The air cleansing and humidifying device may be any conventional apparatus such as a substantially air-tight jar 17 approximately half iilled with water. The continuation tube 15 extends to and terminates at the bottom of the jar 17. The immersed part of the continuation tube 15 is provided with various small holes 18 which permit air within the continuation tube 15 to ow out of the tube 15 through the holes 18 and bubble through the water in the otherwise air-tight jar 17 for cleansing and humidication. A terminal conduit portion 19 is disposed above the surface of the water in the humidifying device 16. The terminal conduit portion 19 communicates directly with an air inlet 20 on a conventional pneumatic pump 21. Thus a channel is provided to accommodate the cleansing, humidiiication and free passage of air from the atmosphere to the pump 21.

The pressurized air required by a human being for respiration, drawn in through the intake conduit 10 is provided, according to the present invention, by the pump or air pressurizing means 21 driven by a conventional electric motor 22 or the like. The pump 21 and motor 22 may be selected from among many of such devices available in the market having sufficient size and capacity to provide air to the lungs at a preselected pressure within the required range of about 3 centimeters of water to 100 centimeters of water pressure in quantities from 5 liters of air per minute to 35 liters of air per minute. The pump 21 and motor 22 may also be provided with adequate suction means to draw a vacuum in the range from 0 of mercury to 20 of mercury pressure.

Air pressurized in the pump 21 liows out of the pump 21 through a high pressure air outlet 23. The high pressure outlet 23 is provided with a pressurized air conduit means or tube means 24 which connects the pump 21 to a suitable, conventional air filter means 25 as for example, a Fiberglas filter housed in a plastic container. The air lter provides a supply of pathogen free filtered compressed air to pro1ect the patient from cross-infection by any harmful organisms in the air compressed by the pump 21.

The pressurized air conduit 24 also connects the air filter 25 with a suitable air pressure accumulator or air cushion means 26 downstream of the air filter 25 so that no unfiltered air can enter and contaminate the air in the cushion 26. The pressure accumulator or cushion 26 can be an air-tight tank or bottle 27 having an inlet port 28 adapted to receive one end of the pressurized air conduit 24 and of suitable volume and capacity to dampen any pressure surges caused by the pump 21.

The pressure accumulator 26 also provides a number of additional outlets for other attachments required for the proper treatment of the patient. Thus a conventional pressure relief means or a pressure relief valve 29, of a suitable biased, pneumatic type is connected to the air cushion 26 in free communication therewith. The pressure relief valve 29 permits air, accidentally pressurized above the preselected pressure level to be discharged directly into the free atmosphere and thereby relieve the eXcess pressure in the system without injuring the lungs.

A suitable pressure gauge 30 is also attached to the air cushion 26 and is adapted to register the air pressure within the air cushion 26. The pressure gauge 30 thus provided permits the patient, or an attendant, to select a specific air pressure of 100 centimeters of water or more above atmospheric pressure to be established in the air cushion means 26 by proper adjustment of the motor 22, pump 21 and the pressure relief valve 29.

Pressurized air ows out from the accumulator 26 through an air supply tube or conduit 31, which may be formed of some texible material, such as rubber or the like. An adjustable throttling valve 32 of conventional design is interposed in the air supply tube 31 near the air cushion 26 to selectively meter the flow of pressurized air and reduce the pressure in the air supply tube 31 downstream of the valve 32 to a continuous pressure selected from between the range of 3 centimeters of Water and 100 centimeters of water above atmospheric pressure, depending on the demands an-d comfort of the person to whom the air is to be supplied. Because of pressure losses inherent in the passage of air through the throttling valve 32, the pressure gauge 30 should ordinarily record a pressure within the air cushion 26 of 100 centimeters of water or more. By providing a pressure of 100 centimeters of water or greater, a continuous stream of pressurized air through the valve 32 up to the pressure limit of 100 centimeters of water is made available for the patient.

The portion of the pressurized air tube 31 downstream of the throttling valve 32 applies air at a continuous positive pressure between 3 centimeters of water and 100 centimeters of water to the lungs by means of intratracheal insulation of the lungs (FIGURE 2). Intratracheal insuiation is accomplished by blowing air into the trachea through a tube introduced into the larynx. Thus an incision 33, known as a superior tracheotomy, is made in the patients windpipe 34, or trachea, between the larynx (not shown) and the isthmus of the thyroid gland (not shown). A cannula or slender tube 35 having a suitable crescent shape such as Dupuis cannula or Trendelenburgs cannula, and formed of silver or the like, is inserted into the incision 33 to provide communication between the lumen, or channel 36 of the trachea, and the air in the air supply conduit 31.

The portion of the cannula 3S disposed outside the neck 37 is provided with an inlet port 38, the axis of which is arranged in a plane generally perpendicular to the axis of the tracheal lumen 36. The inlet port 38 is adapted to receive the air supply conduit 31 carrying the pressurized air from the air cushion 26 to the tracheal lumen 36. Buckles 39 are secured to the exposed portion of the cannula 35 for attachment to a strap 40 which encircles the neck 37 and holds the cannula 35 in position within the trachea 34.

The crescent shape of the cannula 35 provides an outlet 41 disposed downwardly within the tracheal lumen 36 to blow the pressurized air received from the air supply tube 31 toward the lungs of the afflicted person. Thus a continuous stream of air at a preselected pressure between the range of 3 centimeters of water and 100 centimeters of water above atmospheric pressure is supplied to the lungs.

The apparatus shown in FIGURE 1 can also be used to aspirate waste matter from the tracheal lumen 36 and the cannula 35. If the respiration device is to be used to aspirate matter, it is necessary to disconnect the air supply conduit 31 from the inlet port 38 of the cannula 35 and attach thereto the open, upstream end of the intake conduit 10.

In operation, during articial respiration, air is drawn from the free atmosphere into the intake tube 1t) through the separation device 11 and the air cleansing and humidifying device 16 to the air inlet 20 of the pump 21 in the manner hereinbefore described. The pump 21 raises the air pressure to a pressure level of centimeters of water or more to provide a continuous stream of clean, pressurized air. The pressurized air, owing through the pressurized air conduit 24 is filtered in the filter means 25 and delivered to the air cushion means 26. The maximum pressure accumulated within the air cushion means 26 is regulated by adjusting the pump 21, the motor 22 and the pressure relief valve 29. The throttling valve 32 in the air supply tube 31 throttles or reduces the actual air pressure applied to the lungs to a suitable value between the range of about 3 centimeters of water and 100 centimeters of water above the ambient atmospheric pressure. The specific air pressure selected Within the range will, of course, depend on the oxygen requirements of the individual patient.

The continuous stream of pressurized air is applied directly to the patients trachea or windpipe through a cannula 35 and is controlled by the operation of the glottis valve (not shown) in the throat, at the will and pleasure of the patient. Thus the glottis valve in the throat, disposed in the tracheal lumen 36 above the incision 33 accommodating the cannula 35 is closed by the patient to permit air pressure to increase within the lungs by the continuous positive air pressure supplied by the pump 21 in the manner hereinbefore described. If the patient has lost control over the respiratory muscles, exhalation is accomplished by releasing the glottis valve in the throat to permit the normal recoil of the thorax or chest to compress the lungs and force the insuflating air out of the lungs and into the atmosphere through the nose and mouth in the usual manner. Exhalation, according to the invention, is accomplished while a continuous stream of air at a positive pressure is being applied to the lungs through the cannula 35, thereby always maintaining a positive pressure of 3 centimeters of water above atmospheric, or more, within the lungs at all times.

If the physical needs of the patient are such as to require the aspiration of matter from the respiratory system, the separation device 11 is required. Thus according to the invention, air supply tube 31 may be detached from the inlet port 38 of the cannula 35 as previously described. The intake conduit 10 is attached to the inlet port 38 in the cannula 35 to suck waste matter from the lungs and the cannula 35. The terminal conduit portion 19 of the continuation tube 15, communicating with the air inlet 20 of the pump 21, as previously described, creates a subatmospheric pressure in the air-tight jar 12 forming the separation device 11. The sub-atmospheric pressure thus established in the jar 12 sucks matter into the jar 12 yfrom the tracheal lumen 36 and the cannula 35 through the discharge portion 13 of the intake conduit 10. Aspirated solid and fluid matter 42 pours, under gravita- 5 tional inuence, to the bottom of the otherwise air-tight jar 12, while gaseous matter is sucked out of the jar 12, through the suction portion 14 of the intake conduit 10 in the manner hereinbefore described.

As is apparent from the foregoing, the present invention provides a compact and inexpensive apparatus for artiiicial respiration operating according to entirely new principles.

While a representative embodiment of the present invention has been shown and described for purposes of illustration, various changes and modifications can be made therein as pointed out above without departing from the principles of this invention. Therefore, all such changes and modications are included lwithin the intended scope of the invention as deiined by the following claims.

I claim:

1. A method of artificial respiration, comprising the steps of inserting a hollow air-conducting tube into the trachea at a point between the glottis and the lungs, the tube forming a substantially airtight seal with an articial opening in the wall of the trachea While leaving the interior of the trachea unobstructed, and supplying air through the tube to the trachea at a pressure and volume per unit time such that when the glottis is closed the lungs are inated and when the glottis is open the inflated lungs are deflated, expelling air through the trachea and upper respiratory tract, the supply of air through the tube t the trachea being substantially constant as to pressure and volume per unit time during both iniation and deflation of the lungs, whereby the patient can control his own breathing notwithstanding paralysis of the diaphragm by alternately closing and opening the glottis.

2. A method as set forth in claim 1 in which said air is pressurized at a rate of between liters and 35 liters per minute to a gauge pressure of between about 3 centimeters of water and 100 centimeters of water.

3. A method as Set forth in claim 1 further comprising the step of aspirating matter from the respiratory system after said air has been expelled.

4. A respirator consisting of a hollow air-conducting tube for insertion into the trachea at a point between the glottis and the lungs and forming a substantially airtight seal with an artiticial opening in the wall of the trachea and dimen- `sioned to leave the interior of the trachea unobstructed to the passage of air therethrough, and

an air-supply system for maintaining a continuous unidirectional supply of air to the tube, the air -supply system comprising air-supply means having a capacity of not less than 5 liters of air per minute for supplying air through the tube to the trachea at a pressure of not less than 3 centimeters of water such that when the glottis is closed, the lungs are inflated, and when the glottis is open, the inflated lungs are deliated and air from the lungs is expelled through the trachea and upper respiratory tract, whereby the patient can control his own breathing notwithstanding paralysis of the diaphragm by alternately closing and opening the glottis;

an accumulator connected to receive air tlow from the air-supply means for reducing pressure and air 110W variations ofthe air, and

means for maintaining the pressure of the air supplied to the tube at a lsubstantially constant positive pressure of between 3 and 100 centimeters of water thereby precluding bidirectional ow of air in the hollow tube.

5. A respirator as set forth in claim 4 further comprising suction means for removing phlegm and other liquids from the lungs as required by the patient.

6. A respirator as -set forth in claim 5 further comprising a separation device associated with said suction means for separating said phlegm and other liquids from the air expelled from the lungs.

7. A respirator as set forth in claim 4 in which said air-supply means includes filter means for cleansing said arr.

8. A respirator as set forth in claim 4 further cornprising pressure relief means operatively associated with said accumulator means and set to vent said accumulator means to atmosphere at a given gauge pressure within said accumulator means exceeding centimeters of water.

9. A respirator as set forth in claim 8 in which the pressure maintaining means includes a throttling valve operatively associated with said accumulator means and said tube for reducing the pressure of the air fiowing from said accumulator means to said tube.

References Cited UNITED STATES PATENTS 1,169,996 2/1916 Prindle 128-29 1,209,846 12/1916 Kells 12S-276 2,269,904 1/1942 Erickson 12S-276 2,584,450 2/1952 Holt et a1 12S- 203 2,752,917 7/1956 Moller 128-184 2,770,232 11/1956 Falk 128-29 2,845,928 8/1958 Denton 128--191 RICHARD A. GAUDET, Primary Examiner. C. F. ROSENBAUM, Examiner. 

1. A METHOD OF ARTIFICIAL RESPIRATION, COMPRISING THE STEPS OF INSERTING A HOLLOW AIR-CONDUCTING TUBE INTO THE TRACHEA AT A POINT BETWEEN THE GLOTTIS AND THE LUNGS, THE TUBE FORMING A SUBSTANTIALLY AIRTIGHT SEAL WITH AN ARTIFICIAL OPENING IN THE WALL OF THE TRACHEA WHILE LEAVING THE INTERIOR OF THE TRACHEA UNOBSTRUCTED, AND SUPPLYING AIR THROUGH THE TUBE TO THE TRACHEA AT A PRESSURE AND VOLUME PER UNIT TIME SUCH THAT WHEN THE GLOTTIS IS CLOSED THE LUNGS ARE INFLATED AND WHEN THE GLOTTIS IS OPEN THE INFLATED LUNGS ARE DEFLATED, EXPELLING AIR THROUGH THE TRACHEA AND POWER RESPIRATORY TRACT, THE SUPPLY OF AIR THROUGH THE TUBE TO THE TRACHEA BEING SUBSTANTIALLY CONSTANT AS TO PRESSURE AND VOLUME PER UNIT TIME DURING BOTH INFLATION AND DEFLATION OF THE LUNGS, WHEREBY THE PATIENT CAN CONTROL HIS OWN BREATHING NOTWITHSTANDING PARALYSIS OF THE DIAPHRAGM BY ALTERNATELY CLOSING AND OPENING THE GLOTTIS.
 4. A RESPIRATOR CONSISTING OF A HOLLOW AIR-CONDUCTING TUBE FOR INSERTING INTO THE TRACHEA AT A POINT BETWEEN THE GLOTTIS AND THE LUNGS AND FORMING A SUBSTANTIALLY AIRTIGHT SEAL WITH AN ARTIFICIAL OPENING IN THE WALL OF THE TRACHEA AND DIMENSIONED TO LEAVE THE INTERIOR OF THE TRACHEA UNOBSTRUCTED TO THE PASSAGE OF AIR THERETHROUGH, AND AN AIR-SUPPLY OF AIR TO THE TUBE, THE AIR SUPPLY DIRECTIONAL SUPPLY OF AIR TO THE TUBE, THE AIR SUPPLY SYSTEM COMPRISING AIR-SUPPLY MEANS HAVING A CAPACITY OF NOT LESS THAN 5 LITERS OF AIR PER MINUTE FOR SUPPLYING AIR THROUGH THE TUBE TO THE TRACHEA AT A PRESSURE OF NOT LESS THAN 3 CENTIMETERS OF WATER SUCH THAT WHEN THE GLOTTIS IS CLOSED, THE LUNGS ARE INFLATED, THAT WHEN THE GLOTTIS IS OPEN, THE INFLATED LUNGS ARE DEFLATED AND AIR FROM THE LUNGS IS EXPELLED THROUGH THE TRACHEA AND UPPER RESPIRATORY TRACT, WHEREBY THE PATIENT CAN CONTROL HIS OWN BREATHING NOTWITHSTANDING PARALYSIS OF THE DIAPHRAGM BY ALTERNATELY CLOSING AND OPENING THE GLOTTIS; AN ACCUMULATOR CONNECTED TO RECEIVE AIR FLOW FROM THE AIR-SUPPLY MEANS FOR REDUCING PRESSURE AND AIR FLOW VARIATIONS OF THE AIR, AND MEANS FOR MAINTAINING THE PRESSURE OF THE AIR SUPPLIED TO THE TUBE AT A SUBSTANTIALLY CONSTANT POSITIVE PRESSURE OF BETWEEN 3 AND 100 CENTIMETERS OF WATER THEREBY PRECLUDING BIDIRECTIONAL FLOW OF AIR IN THE HOLLOW TUBE. 